Party Girl

The story behind Sienna's codename originates from her "wild" parties she organized for businessmen and officials in her youth. The reason for this was to record incriminating behavior and information, which would then be sold. After she managed to dupe the US Federal Government's top surveillance expert at one of her parties, she was offered a job. How she became a sniper is unknown.

Party Girl is the functional equivalent of SPECTRE for the Spec Ops faction.